By Kierstin Wesolowski
Disease-risk predictions made by direct-to-consumer (DTC) genetic tests produced contradictory results and provided misinformation to consumers, according to a July 22 report by the Government Accountability Office (GAO).
The findings from the GAO’s yearlong investigation into four genetic testing companies were released to members of the Subcommittee on Oversight and Investigations, one month after the FDA sent warning letters to five companies offering DTC genetic tests. In the letters, the FDA warned that genetics tests are medical devices that require the FDA pre-market approval.
In the GAO investigation, five donors each sent two DNA samples to these genetic testing companies–23andMe, Inc., deCODE Genetics, Navigenics, and Pathway Genomics. One sample contained accurate information about the donor, such as age, race, or ethnicity, while the other contained fabricated information. The risk predictions for 15 common diseases, which included Alzheimer's disease and multiple sclerosis, were then compared among the four companies.
Investigators found that the disease-risk predictions that were based on factual profiles “varied across all four companies, indicating that identical DNA can yield contradictory results depending solely on the company it was sent to for analysis,” according to the GAO report. In one instance, a company predicted a donor had an above-average risk for developing leukemia, while another claimed she had a below-average risk.
They also found that the predictions of risk often times conflicted with the donor’s actual medical history. One company predicted that a colon-cancer survivor had an average risk for developing the disease. In another example, a donor who had had a pacemaker implanted to treat atrial fibrillation received predictions from two companies stating he was at below-average risk for developing atrial fibrillation.
In some cases, the companies claimed the risk predictions couldn’t be determined because the donors were not of “European ancestry,” the report stated. However, this restriction wasn’t explicitly written in the purchase information or on the companyWeb sites. Two of the four companies refused to refund the donors’ money.
“The GAO’s report supports what most geneticists have been warning, that currently the amount of information that can be derived for diagnostic purposes from this genotyping is very small and thus really provides no clear direction to what is the right answer if someone is actually trying to use it to determine risk,” says Jeffery M. Vance, M.D., Ph.D., professor of neurology and chair of the department of genetics at the University of Miami. “Thus, it is not surprising that many different answers were obtained in the [GAO] report.”
Dr. Vance stressed that genomic medicine has now reached the point where it needs to be treated like other clinical entities in development: “It needs to be moved ahead with careful, scientific, evidence-based medicine by those professionals who understand its complexity; it has moved past being just a business opportunity.”
A similar GAO investigation in 2006 found that four other genetic testing companies were providing consumers with results “that were both medically unproven and so ambiguous as to be meaningless,” according to the 2010 GAO report. Subsequently, the CDC, FDA, and FTC had issued warnings to consumers about the validity of these test results.
Read the Aug. 5 issue of Neurology Today
for the complete article on the FDA’s warning to genetic testing companies, “FDA Warns Companies about DTC Genetics Test,” in print and online at www.neurotodayonline.com